Honda Grom Tyga Full System Underbelly Stainless Steel Oval/Carbon End Cap, Short
This full race system has been specifically designed for the Grom to maximise power. Made of stainless steel with spring mounted carbon silencer this system increases performance, saves weight and enhances the looks of the bike. Sounds great too! (A db killer is included)
Feel free to request this product with no TYGA logo. Simply put in the comment box with your order: 'Please supply with no TYGA logo'. 
 
Performance and Dynograph
The blue trace shows the 100% standard Honda MSX125 Grom, compared to the red trace, which is after installing the TYGA Full System set  with no other changes to the stock bike.
A useful increase in peak power and further gains could probably be had with remapping etc.